how to undo all whitespace changes with git

I have a git repo, where I replaced a lot of files locally.

git status now shows many many modified files.

Some are "really modified", others only differ by line endings.

I want the ones that differ only by line endings to go away (git reset them), but I cannot seem to find the linux-piping-foo to make it happen.

Bonus points for how to remove files whose only difference is the executable bit.